138 LOUIS PASTEUR. 



Following up the idea that a connection between 

 the disease and the corpuscles might possibly exist, 

 as other observers had previously imagined, Pasteur 

 declared, in a Note presented to the Agricultural 

 Committee of Alais on June 26, 1865, twenty days 

 after his arrival, that it was a mistake to seek for the 

 corpuscle in the eggs or in the worms. Both the one 

 and the other could carry in them the germ of the 

 disease, without exhibiting distinct corpuscles, visible 

 under the microscope. The evil developed itself espe- 

 cially in the chrysalides and in the moths, and it was 

 in them that search should be made. Finally, Pasteur 

 came to the conclusion that the only infallible method 

 of procuring healthy eggs must be by having recourse 

 to moths free from corpuscles. 



Pasteur hastened to apply this new method of ob- 

 taining pure eggs. Notwithstanding that the malady 

 was universally prevalent, he succeeded, after several 

 days of assiduous microscopic observations, in finding 

 some moths free from corpuscles. He carefully pre- 

 served their eggs, as well as other eggs which had 

 proceeded from very corpusculous couples, intending to 

 wait for what these eggs would produce the following 

 year ; the first would be probably free from corpuscles, 

 while the latter would contain them. He would thus 

 have in future, though on a small scale, samples of 

 originally healthy and of originally unhealthy cultiva- 

 tions, by the comparison of which with the cultivations 



